We found this with my son as well. barely talked, lots of "I don't knows", ornery most of the time. With recovery he got a bit better and now even though he slipped, he seems to talk more and not be so moody. I hate when it feels like pulling teeth just to have a simple conversation. I hope it gets better as time goes and his body rids itself of the toxins.
I know what you mean. Let us keep in touch and learn from each other.
Don't let the slip throw you or your son, off. My conversations with addiction specialists that slips happen and the main thing is to get back on the recovery horse asap so that not too much damage is done.